Problem: Expand. If necessary, combine like terms. $(x+8)(x-8)=$
Notice that this expression has the following special form: $(a+b)(a-b)$ This form expands to what we call "a difference of squares": $( a+ b)( a- b)= a^2- b^2$ Using the above pattern, we get: $\begin{aligned} ( x+ 8)( x- 8)&= x^2- 8^2 \\\\ &=x^2-64 \end{aligned}$